New information shows chlamydia's spread

It's time to increase chlamydia screening in your clinic. Results of a new study show that, despite current screening recommendations, more than 2 million people are infected with chlamydia in the United States.1

To perform the study, researchers affiliated with the Centers for Disease Control and Prevention (CDC) looked at the frequency of gonorrhea and chlamydia infection among 6,632 people ages 14-39 who completed a national survey. They analyzed the information to estimate the frequency of these sexually transmitted disease (STD) infections in the entire U.S. population. They examined the frequency of infection according to patient factors, such as age, sex, race, or ethnic background, and history of previous sexually transmitted infection.

The researchers estimated about two out of every 100 people have chlamydia infection, while fewer than one out of every 400 people have gonorrhea infection. Adolescents had the highest disease burden for gonorrhea and chlamydia compared with other age groups, researchers report.1

"The prevalence data from this study serve as a reminder that chlamydia and gonorrhea pose a serious concern to the health of Americans," says Deblina Datta, MD, medical epidemiologist in CDC's Division of STD Prevention. "STDs often have no symptoms and, therefore, frequently go unrecognized and undiagnosed."

New guidance issued

A new update has been issued for the original 2001 U.S. Preventive Services Task Force (USPSTF) recommendations for screening sexually active adolescents and adults for chlamydial infection.2,3

What are the risks for chlamydia in women? According to the guidance, women are at risk if they have one or more of the following factors:

  • They are 24 years of age or younger and are sexually active.
  • They have previously had chlamydia or another sexually transmitted infection.
  • They have new or multiple sexual partners.
  • They do not use condoms regularly.
  • They exchange sex for money or drugs.2

All sexually active, nonpregnant women age 24 years or younger should be screened for chlamydia, advises the current guidance. This represents a change in age from the previous USPSTF recommendation on chlamydia screening and was done to align the recommendation with the evidence in support of screening, including national surveillance data assembled by the CDC. Nonpregnant women who are age 25 years or older should be screened only if they are at increased risk for infection.2

All pregnant women age 24 years or younger and older pregnant women who are at increased risk for chlamydial infection should be screened, according to the new guidance. There is not enough available information to know whether men should be screened routinely for chlamydia, the guidance concludes.2

Better implementation of current screening and prevention efforts are critical to ensuring that young people — especially women — do not suffer the long-term effects of untreated chlamydia, says Datta.

Chlamydia screening for women is critical, she states. When left untreated in women, chlamydia can cause pelvic inflammatory disease, ectopic pregnancy, chronic pelvic pain, and infertility as long term outcomes, Datta says. In the short term, infection can cause cervicitis and urethritis, she notes. STDs such as chlamydia and gonorrhea also may increase the risk for HIV transmission, she adds.

What puts teens at risk for STDs such as chlamydia and gonorrhea? Datta points to such likely factors as more unprotected intercourse, increased substance use, and less frequent health care-seeking behavior. Adolescent females may be more susceptible to infection due to increased ectopy of the adolescent cervix, she notes.

What are your options when it comes to boosting screening rates in your clinic? Results from a randomized trial provide evidence that use of exam room screening reminders, physician opinion leaders, and screening measurement and feedback to physicians can improve chlamydia testing rates in women making preventive care visits.4

Researchers randomized 23 primary care clinics, all part of the Group Health Cooperative managed care plan in Washington state, to receive standard care or intervention care. Clinic-level intervention strategies included use of clinic-based opinion leaders, who educated clinicians on screening and counseling of young women; computerized reports that provided physicians with feedback on the proportion of eligible women screened by them; and exam room reminders to screen young women ages 14-25 for chlamydia infection.

While the clinic-level intervention did not significantly affect overall chlamydia testing, testing rates increased significantly for women making preventive care visits. Screenings were increased by 23% for visits for Pap tests and by 22% for physical exam visits. Using a chart prompt to screen for chlamydia (which was delivered to a random subsample of women) had no significant effect, researchers report.4

A combination of clinic-level change and patient activation strategies may improve health plan-wide testing, particularly among asymptomatic women, researchers conclude.4


  1. Datta SD, Sternberg M, Johnson RE, et al. Gonorrhea and chlamydia in the United States among persons 14 to 39 years of age, 1999 to 2002. Ann Intern Med 2007; 147:89-96.
  2. U.S. Preventive Services Task Force. Screening for chlamydial infection: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2007; 147:128-134.
  3. Meyers DS, Halvorson H, Luckhaupt S, et al. Screening for chlamydial infection: An evidence update for the U.S. Preventive Services Task Force. Ann Intern Med 2007; 147:135-142.
  4. Scholes D, Grothaus L, McClure J, et al. A randomized trial of strategies to increase chlamydia screening in young women. Prev Med 2006; 43:343-350.